Structural characterization of defects in EFG- and HVPE-grown β-Ga2O3 crystals

Japanese Journal of Applied Physics ◽

10.35848/1347-4065/ac4b6b ◽

2022 ◽

Author(s):

Osamu Ueda ◽

Makoto Kasu ◽

Hirotaka Yamaguchi

Keyword(s):

Electron Microscopy ◽

Chemical Etching ◽

Focused Ion Beam ◽

Ion Beam ◽

Hydride Vapor Phase Epitaxy ◽

Etch Pits ◽

The Status ◽

High Resolution Tem ◽

Generation Mechanisms

Abstract This paper reviews the status of characterization of defects in β-Ga2O3 crystals grown by edge-defined film-fed growth and hydride vapor phase epitaxy using chemical etching, scanning electron microscopy, focused ion beam scanning ion microscopy, X-ray topography (XRT), and transmission electron microscopy (TEM). The observed defects are classified into four types: dislocations, stacking faults (SFs), twins, and plate-like nanovoids (PNVs). First, we present the detailed characterization of dislocations in the crystal by chemical etching, XRT, and TEM, and discuss possible slip systems. Next, we describe XRT analyses of two types of SFs: SFs 1 lying on the (2 ̅01) plane and SFs 2 on the (111) and (11 ̅1) planes. We describe the results for twins found in crystals via high-resolution TEM and electron diffraction analysis, and PNVs corresponding to etch pits on the (010) plane. Finally, we discuss possible generation mechanisms of the defects and their influence on device characteristics.

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FIB-TEM Characterization of Locally Restricted Implantation Damage

MRS Proceedings ◽

10.1557/proc-738-g7.14 ◽

2002 ◽

Vol 738 ◽

Author(s):

Heinz D. Wanzenboeck ◽

Stefan Harasek ◽

Wolfgang Brezna ◽

Alois Lugstein ◽

Helmut Langfischer ◽

...

Keyword(s):

Electron Microscopy ◽

Focused Ion Beam ◽

Ion Beam ◽

Defect Analysis ◽

Multilayered Structures ◽

Damage Layer ◽

Implantation Damage ◽

Transmission Electron ◽

High Resolution Tem

ABSTRACTImaging critical features by using transmission electron microscopy (TEM) or scanning electron microscopy (SEM) provides a versatile approach for nanostructure characterization. The combination of focused ion beam (FIB) technology for exposing defective sites beneath the surface is shown. Reliability testing and defect analysis by localized characterization of multilayered structures is demonstrated. TEM-imaging of a transistor gate with a locally confined radiation damage demonstrates target preparation by FIB yielding high-resolution TEM samples. The TEM imaging requires a longer sample preparation but provides high image quality (TEM). Investigation of materials previously processed with FIB revealed amorphization damage by the high energetic Ga-ion beam. This damage layer with a thickness in the range of 50 to 100 nm was confirmed in simulation. This disadvantageous damage by amorphization originating from FIB preparation of the cross-section could be removed by soft sputtering with a 250 V Ar+ ion beam. This combined method using FIB for microsample preparation and TEM for imaging and analysis was proven to be a powerful tool the exploitation of nanostructured devices and for defect analysis on a highly localized scale.

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Characterization of transport mechanisms for controlled release polymer membranes using focused ion beam scanning electron microscopy image-based modelling

Journal of Drug Delivery Science and Technology ◽

10.1016/j.jddst.2020.102136 ◽

2020 ◽

pp. 102136

Author(s):

Shawn Zhang ◽

Gerard Byrne

Keyword(s):

Electron Microscopy ◽

Focused Ion Beam ◽

Ion Beam ◽

Polymer Membranes ◽

Scanning Electron Microscopy Image ◽

Transport Mechanisms ◽

Microscopy Image ◽

Controlled Release Polymer ◽

Scanning Electron

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Fabrication and Characterization of Solid Composite Yarns from Carbon Nanotubes and Poly(dicyclopentadiene)

Nanomaterials ◽

10.3390/nano10040717 ◽

2020 ◽

Vol 10 (4) ◽

pp. 717 ◽

Cited By ~ 4

Author(s):

Wenbo Xin ◽

Joseph Severino ◽

Arie Venkert ◽

Hang Yu ◽

Daniel Knorr ◽

...

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Focused Ion Beam ◽

Ion Beam ◽

Strengthening Mechanism ◽

Composite Yarn ◽

Transmission Electron ◽

Frictional Forces ◽

Mechanical Consolidation

In this report, networks of carbon nanotubes (CNTs) are transformed into composite yarns by infusion, mechanical consolidation and polymerization of dicyclopentadiene (DCPD). The microstructures of the CNT yarn and its composite are characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and a focused ion beam used for cross-sectioning. Pristine yarns have tensile strength, modulus and elongation at failure of 0.8 GPa, 14 GPa and 14.0%, respectively. In the composite yarn, these values are significantly enhanced to 1.2 GPa, 68 GPa and 3.4%, respectively. Owing to the consolidation and alignment improvement, its electrical conductivity was increased from 1.0 × 105 S/m (raw yarn) to 5.0 × 105 S/m and 5.3 × 105 S/m for twisted yarn and composite yarn, respectively. The strengthening mechanism is attributed to the binding of the DCPD polymer, which acts as a capstan and increases frictional forces within the nanotube bundles, making it more difficult to pull them apart.

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